The deposition of unconsolidated deposits by aeolian, marine, or fluvial processes, when the quantity or calibre of the load is greater than the competence of the transporting medium to carry it, or as a result of mass movement. See Daniels (2003) Geomorph. 56, 3–4 on aggradational pedogenesis on floodplains. For aggradation surface, see Wang and Grapes (2008) Geomorph. 96, 1–2.